


A Secret Between Sister's

by frozentiger



Category: Persona 5
Genre: Bestiality, Creampie, F/M, Knotting, Oral Sex, Semi-Public Sex
Language: English
Status: Completed
Published: 2021-02-15
Updated: 2021-02-15
Packaged: 2021-03-16 16:13:55
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,918
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29456547
Author URL: https://archiveofourown.org/users/frozentiger/pseuds/frozentiger
Summary: Makoto and Sae are lonely, a dog named Sam helps with that.
Kudos: 25





	A Secret Between Sister's

**Author's Note:**

> This was a story I wrote about 2 months ago but wasn't happy with, after some feedback I made rewrites and I think it turned out pretty well.

It had been a few years since the Niijima sisters lost their father, In what seemed like a day their whole world was shaken to its core. The elder sister Sae chose to bury her sorrows with work. Though she managed to achieve a lot very quickly professionally her home life suffered for it. Being left to care for her younger sister was a burden, she did love her sister but the stress of work and caring for another was too much sometimes. Sae did feel bad leaving her sister alone so much but it was what needed to be done.

Like many nights Sae came home late. As she stepped in the door Makoto came to welcome her home before bed.

“Hey, sis, welcome home.” The younger sister's voice seemed devoid of any emotion.

Sae dropped onto the couch and began taking off her heels. “Hey, did you finish your schoolwork?”

Makoto nodded and silently said, “Yes.” before going to bed. The elder sibling let out a sigh and leaned back into the soft couch.

Sae could tell her sister was lonely, in a way she was feeling that as well. Unfortunately, she couldn't take time off work though, as a woman she had to work ten times harder to earn her place and failure isn't an option. Then she got to thinking maybe having a pet would cheer Makoto up. While Sae herself wouldn't be able to care for the animal much with work she figured Makoto could and would probably even enjoy doing something other than studying. It may even give Makoto an idea of what Sae had to deal with, balancing work with taking care of another.

The next morning, while the two sisters were silently eating breakfast before work and school, Sae decided to propose the idea of a pet.

“Hey, Makoto, how do you feel about cats?”

Makoto looked up from her meal. “I’m more of a dog person.”

“O-oh then how would you feel about maybe getting a dog?” Sae asked.

“Are you serious sis? I didn't think you would want a pet?” Makoto was shocked as Sae never seemed interested in animals before.

“Well I get busy a lot with work and figured you could use the company, but if we do get one it would be on you to take care of it ok?” Sae was thinking of something easier like a cat but if Makoto was willing to care for it she didn't mind a dog instead.

After breakfast the two agreed to go with an older dog as a puppy was too much work, they planned to go on a day Sae had time off and adopt one.  
About a week passed and Makoto was getting more and more excited at the idea. She never had a pet before despite being fond of animals so this was an opportunity she wouldn't let pass. Even if it was a lot of work Makoto would take it on like she always had. That afternoon Sae managed to get off work early, though she would have to make up for it tomorrow it gave her the time to take Makoto to a shelter.

Once they got to the shelter the sisters spent a few minutes looking at the dogs up for adoption. There were plenty of friendly dogs but the one that caught both the sisters’ attention was a large male Dobberman with the name Sam who was extremely friendly and well behaved. Believing they had found the perfect pet, the Niijima’s got the paperwork done and were able to take Sam home that very night.

When they arrived at home Sae went back out to get some things for the dog giving Makoto time to help Sam adjust to his new home. Sam went around sniffing various things before walking up the Makoto clearly wanting attention. Makoto gave the dog soft pets and rubs behind the ear. After a few seconds of this, Sam’s snout went under the young teen’s skirt. 

Makoto panicked when she felt the dog's hot breath on her crotch and pulled his snout out. “Hey bad boy, don't just go sniffing wherever you please!”

Sam gave her a puppy-eyed look making her melt and instantly forgiving him. “It's ok you didn't know any better,” Makoto said with a smile as she continued to pet the dog.

About half an hour later Makoto got a text from her sister, Sae said she had got called into work and wouldn't be home till at least midnight and that she would bring the dog stuff when she got home. Normally this would upset Makoto but as she sat on the couch with Sam snuggled up to her feet she felt completely fine.

As the night went on Makoto had started watching a movie, Half-way through there was a spicy sex scene. It had been a while since Makoto had masturbated and her nether regions began getting hot. Seeing as her sister was gone for the night Makoto brought her hand underneath her skirt. She began to rub her pussy through her black tights and panties.

Sam woke from his sleep from the sound of his owner making soft moans and taking hot breaths. Standing up to investigate, the Dobberman pushed his snout into where his owner's hands were touching. Makoto let out a loud yelp as she felt Sam’s warm breath on her, She went to push his snout away but before she could the dog started to lap as her crotch.

Makoto tried to take control of the situation and stop Sam but he had found a smell he liked and began lapping his tongue against her. She was already feeling a bit horny because of the movie and even through her tights and panties she could feel his warm wet tongue. Her body melted against the dog’s assaults and slowly her attempts to push Sam away become weaker and weaker. It felt so good for the younger Niijima sister and even though she knew it was wrong she thought to herself that since there was no one around it wouldn't be that big of deal to let him do it for a bit longer right?

Laying her head back and closing her eyes she started to let out lewd moans as the dogs tongue eagerly tried to taste her pussy. Her panties were soaked now and not only because of the dog, its tongue was hitting her clit through the fabric making her quickly approach an orgasm. grabbing the dogs head and forcing his snout against her pussy, Makoto began biting her knuckles to hold back a scream as she came hard from the dogs tongue, Sam for his part got to enjoy tasty juices leaking through the clothing.

“Oh god what did i just do!?” Makoto felt the shame of her actions immediately after she came down from her orgasm.

Before she could do anything else she felt Sam rip her tights with his teeth. She pulled him off her and tried to regain control of the situation. Makoto tried getting off the couch but Sam being a large dog jumped up and pushed her back down. The dog continued to attack her pussy through the fabric of her panties. Makoto was losing the will to fight back. Her body wanted it so badly. She looked over and noticed his red cock poking out and twitching. 

The young girl's mind became cloudy and on instinct without even noticing what she was doing Makoto raised her hips and pulled the black ripped tights and panties down. Sam gave her pussy direct licks making the young girl moan into the couch. The dog then brought its two front paws up onto the furniture and began trying to bury its bone so to speak.

This was wrong she knew that but the warm rod poking her ass was making those thoughts be pushed aside for ones of lust. He was having a hard time finding his place so she hesitantly reached back to grab hold of his shaft. When she touched it she was shocked at its large size and girth.. Once she had hold she lined him up with her cunt, his shaft slowly pushed past her lips.

“Ah g-go slow boy it hurts.” Makoto tried pleading with the canine but being an animal Sam did not listen at all and began slamming rough and quickly into her virgin pussy.

She tried using the couch to muffle her cries, at first the pain of being penetrated was a lot but slowly with each thrust of Sam’s cock her body adjusted and that pain became intense pleasure. The entire time she was fucked by the hound he showered her face with licks of affection. At first Makoto resisted but soon her hips began to push back with his thrust and she started returning his kisses and licks.

“Good boy, please don't stop,” Makoto chanted into the cushion as her insides were pounded into.

After only a few minutes she started to feel him throb inside her. For a moment her rational thoughts came back and told her to make him pull out before he tried to knot her. Before she could stop him though Sam with one last hard deep push forward sunk his knot past her pussy lips. Makoto lost her breath for a moment as her cunt was sealed. 

A few seconds later and with a whine Sam began to cum. She squealed in delight as warm gooey sperm filled her womb and then when that was full her entire pussy as well. Makoto came harder than she ever had before, making her insides squeeze every drop out of the canine’s balls. Sam got off the couch and tried to walk away after he was satisfied but his knot was still in her.

“W-WAIT OW IT HURTS SAM!” Makoto yelled and begged but the dog didn't care and pulled until he was free from her. Makoto gasped as his knot and cock were yanked out and she moaned as globs of thick cream poured out from her pussy like a faucet.

The young girl laid on the couch as her spread pussy leaked a pool of thick cum. Makoto knew when her body regained strength she was gonna have to try and figure out how to clean the couch but it would be sometime before she could move.

When Sae got home she was confused as to why the couch smelled of cleaning products but assumed Makoto must have just been careless and spilled something.

After that night a few days past, Makoto tried to forget but every time she was alone with Sam her mind was clouded with obscene thoughts. The shame of it was overwhelming her but she couldn't go to anyone for help.

Sae noticed her sister was acting strange. Figuring it may just be stress, she told Makoto to go out with her friends after school as she would be off work at a reasonable time for once and could watch the dog. Plus it would be a good opportunity to bond with the new pet too she thought.

When Sae arrived home Sam was sleeping on a dog bed in the living room. Sae decided to go ahead and take a shower after a long day. In the bathroom the older Niijima was getting undressed before her stomach growled fiercely. It was then she remembered that she had skipped lunch. Before she went into the shower Sae decided to get a snack from the kitchen. She was almost nude being in only her lacy black bra, panties and thigh highs but since no one else was home she would be fine walking around the house in that she thought.

Once in the kitchen she was making a quick bite before her shower when she dropped something that rolled under the fridge. Letting out a huff of annoyance Sae got on her knees and began trying to reach under for the dropped item.

Sam woke up and heard someone in the kitchen so the dog made its way over. When he entered the kitchen he was met with the view of Sae’s round pale butt on full display shaking as she tried to grab something under the fridge. Sam began drooling at the sight and quickly became erect.

Sae almost had a grasp on what she dropped when she felt a warm tongue lap at her panties. She was left stunned for a moment as it had been awhile since she received any attention down there. She spun around and pushed Sam away. Sitting on the kitchen floor Sae was breathing heavily, her body felt hornier than it had ever been before. it had been awhile and she was stressed with work so her body wanted sexual relief badly. Her rational side told her to just go cooldown in the shower but her horny side wanted a cock in her pussy more than anything.

“No, this is stupid. Its a dog I cant fuck a dog-” Before she could finish her sentence Sae noticed Sam’s thick red cock. Its size and length were beyond any man she had slept with and the temptation was mounting.

Sae tried to gain the self control to end this obscenity but fighting her very horny body was a losing battle. Her mind then rationalized that if she just had oral sex with the dog it wouldn’t count. She knew this was a poor excuse but her twisted desires overtook all logic.

“O-ok boy lay down and we can both feel good.” The dog obediently let his master push him onto his back.

Once the dog was laying down, Sae pulled her panties off and straddled the hound. Pushing her pussy against Sam’s snout he wasted no time getting to work with his tongue. As her pussy was worked over by the rough dog tongue Sae brought her face close to his shaft and wrapped her hands around it. The way Sam’s cock felt was incredible to Sae. His cock was thick and long with an intense heat that no human dick had. Her mouth was salivating, wanting to taste the meat.

With a deep breath Sae pushed aside her thoughts and committed herself to just indulge in the taboo situation. Giving his veiny cock testing licks Sae quickly found she liked the strange taste. After showering the dog cock in licks Sae took it into her mouth. Slowly she bobbed her head up and down the shaft as her tongue swirled trying to reach every inch of the cock.

Sam was whining and panting as his bitch began throating his dick. His cock was milked throughly by Sae’s tight throat and massaged by her soft tongue. Her lewd moans were all the encouragement the canine needed to happily continue lapping her pussy juices.

When she felt him start throbbing wildly Sae took the cock into the back of her throat and gagged on it while her tongue remained licking the shaft. Without warning shots of cum began to shoot down Sae’s throat. She was unable to move a muscle as her over sensitive cunt began cumming from Sam’s tongue.

Sae whined like a kitten with each shot of cum that filled her stomach and Sam enjoyed having his female’s juices shot out onto his snout. They stayed there drinking down one anothers cum for minutes.

Afterward, Sae was lying on the ground next to Sam when she noticed he was still very erect.

“Hey boy do you wanna join me in the shower?” Sae spoke now with complete lust.

Sam responded with a wagging tail and a happy bark. And after regaining some energy Sae got up and wobbled over to the bathroom with the dog right behind. Stepping into the hot shower Sae laid down in the tub letting the water pour over her as she called over Sam. The dog without any hesitation got into the tub with her and with some help sunk his cock into her pussy. The elder sister had completely forgotten about her earlier promise of only doing oral. For almost an hour Sam fucked Sae in the shower as she wrapped her legs tight around the hound ensuring he gave deep thrust. She even let him knot her a few times. They only stopped when the water was cold.

After their shower and countless amounts of orgasms Sae fell into her bed and passed out. When she awoke with a clear mind she was filled with regret. This was a secret she had to take to the grave.

In the days that followed Makoto found it harder to repress her urges, she would often find herself thinking about Sam’s penis and the feeling of it inside her. One night while Sae and Makoto were watching TV on the couch the elder sibling fell asleep after a long work day. Sam came up and put his head on Makoto’s lap whining for attention. Makoto embraced the taboo thoughts she was plagued with and even though her sister was only a few feet away she began quietly giving the dog a blowjob.

Makoto was trying to be quiet so as to not alert her sister. Slowly she would lick the head and shaft of the canine’s penis before then taking it past her soft lips and sucking gently on it. 

Sam was just laying down with his tongue out panting as his cock received a luxury cleaning from Makoto’s mouth.

“Shh quiet boy you cant wake sis up.” Makoto whispered to the excited dog. Returning to her task she fondled the dog’s scrotum while she slurped down his meat earning her plenty of precum to lap up from his throbbing tip.

Feeling the red hot cock in her mouth expanding, Makoto worked her throat and tongue as much as she could. For her efforts spurts of slimy warm cum coated her tongue letting her enjoy the rich taste. When he had finished cumming in her mouth Makoto gave Sam’s cock a power wash with her tongue. The young Niijima spent the night slurping on dog cock trying her best to not wake her sister. That night she was able to drink her fill of doggy cum.

It didn't stop there though as later that week Sam would get to claim the elder Niijima once again.

When Sae got home from work that night she had decided to take Sam on a walk. For the most part it was a normal nightly stroll through a park when all of the sudden the dog kept trying to jump on Sae. At first she thought he was just trying to play but then she felt something hit her leg, She noticed then that the canine did want to play just not the way she thought.

Sae on instinct pushed the dog off, but as she stood there staring at its veiny twitching shaft the memories of how good it felt flooded her mind. With a nervous gulp she led Sam into some dark bushes. She bent down and began to stroke his cock, he returned her affection to his rod with some licks to her face.

“What the fuck am i doing…” Sae spoke softly, almost as if he knew what she meant Sam gave her more reassuring licks.

Slowly Sae’s willpower faded and she found herself bent over on the grass pulling down her pants and panties. The chill of the cold night air on her exposed pussy made her shiver but that was nothing to the jolt she felt as Sam mounted her and began to prod at her pussy with his pulsing dick.

Reaching around Sae took hold of the dog's penis and helped insert it into her. Within seconds she was a panting mess as Sam hammered her poor pussy with no restrain. “Good boy make me your bitch.” The words Sae spoke almost sounded like they came from someone else. She couldn't believe this here she was on her knees in a park getting fucked by a dog. If it wasn't for the pleasure her pussy felt she would probably be dying of shame at the moment. 

“All my life i've worked hard to make something of myself and now i'm letting a dog have its way with me…” These thoughts repeated in Sae’s mind as Sam knotted and pumped her womb full of sperm.

Once they were done Sae got up, pulled her pants back up and continued her walk with the dog like nothing had happened, But inside something had changed with the older woman her pride had been thrown away she didn't care anymore this was too good to stop now.

From then on both siblings continued to have sex with the dog in secret, the guilt they felt was washed away as they only cared about chasing these twisted desires. It wouldn't remain a secret for long though as one day while Makoto thought her sister would be working late Sae had walked in on her sucking Sam’s cock.

For a moment both of them froze. Makoto started berating herself for putting her hornyness over being careful. Meanwhile Sae’s brain was a mess, It was one thing for her to do such acts but the thought that her little sister was as well made her dizzy.

Sam being a dog and not understanding the situation continued to push his cock into his female’s warm mouth. Makoto pulled her lips off the cock with a pop and tried to explain but Sae put her hand up making her stop mid-sentence.

“You don't have to explain, T-the truth is I've been doing such ridiculous acts as well…” Sae expected her sister to judge her, to look down on her. Even if they were both guilty of the same crime as the older sibling Sae should have been better than giving in to such temptations.

For Makoto’s part, she just felt relieved that this didn't need to be something she kept to herself anymore, it could be their secret as sisters. “It's ok sis, I guess we just both were lonely and Sam filled the void in more ways than we originally had planned.” Makoto tried to reassure her sister that their actions were justified. 

While perhaps at one point Sae would reject the notion that such a thing could ever be justified now her mind looked for any way it could to rationalize this. “Yes you're right I think,” Sae said with conviction.

Makoto stroked Sam’s cock and angled it towards her sister in an offering fashion. “Care to join me sis?” Both girls smiled at this and within seconds Sae had shed her work clothes and like her sister was on her knees slurping on dog cock like there was nothing wrong with it.

Both girls took turns deepthroating the red penis, multiple times they enjoyed shots of cum pouring into their mouths and later that night they even took turns having the dog knot them. The night ended with both sisters' wombs and stomachs full of sperm and Sam got to enjoy a night of royal cock treatment from both of his bitches.

The Niijima sisters would indulge in their sick desires every night from then on, it became their little secret that they could only ever share with each other. Their stress and worries washed away and the siblings felt closer than ever before.

**Author's Note:**

> https://twitter.com/FrozenTiger10 follow for WIP updates and story polls :D


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